أَخْبَرَنِي مُحَمَّدُ بْنُ إِسْمَاعِيلَ بْنِ إِبْرَاهِيمَ، عَنْ يَزِيدَ، عَنْ سُلَيْمَانَ التَّيْمِيِّ، عَنِ الْحَسَنِ، عَنْ أَبِي مُوسَى، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " إِذَا تَوَاجَهَ الْمُسْلِمَانِ بِسَيْفَيْهِمَا فَقَتَلَ أَحَدُهُمَا صَاحِبَهُ فَهُمَا فِي النَّارِ " . قِيلَ يَا رَسُولَ اللَّهِ هَذَا الْقَاتِلُ فَمَا بَالُ الْمَقْتُولِ قَالَ " أَرَادَ قَتْلَ صَاحِبِهِ " .
It was narrated from Abu Musa that: The Prophet [SAW] said: "If two Muslims confront each other with swords, and one kills the other, they will both be in Hell." It was said: "O Messenger of Allah, (we understand about) the killer, but what about the one who is killed?" He said: "He wanted to kill his companion." Translation Not Available
Book Ref: Sunan An Nisai Book 37 Hadith 4118
Web Ref: Sunan An Nisai Vol 5 Book 37 Hadith 4123